We have recently demonstrated that metabolic energy is required for insulin stimulation of glucose transport in isolated adipocytes of the rat. It is our purpose to characterize the nature of the energy requirement as a means of understanding the mechanism of insulin action at a molecular level. A variety of inhibitors will be tested for their ability to inhibit ATP generation in isolated adipocytes and at the same time for their ability to block insulin-stimulated glucose transport as assessed in an isolated membrane preparation. We will then attempt to develop a subcellular (homogenate) system which will respond to insulin in the presence of a variety of energy donors. If this works, we plan to examine the system responsible for the transfer of energy (? high energy phosphate) to the membrane and the changes involved in making them insulin responsive. Finally, as a result of our earlier work, we will examine the mechanism by which 2-deoxyglucose lowers ATP levels in isolated fat cells.